STARTNEWERA Phase II Trial Shows Promising 5-Year Outcomes for Stereotactic Radiotherapy in Advanced Lung Cancer
Key Insights
The STARTNEWERA phase II trial demonstrates that stereotactic ablative radiotherapy (SAbR) achieves 46% five-year overall survival and 26% progression-free survival in unresectable locally advanced non-small cell lung cancer patients unfit for concurrent chemoradiotherapy.
The study enrolled 50 patients with 76% having central tumors, showing no grade 3 toxicity events over a median 72-month follow-up period.
Key predictors of local recurrence included squamous cell carcinoma histology and SAbR doses below 40 Gy, with 92% of oligometastatic recurrences successfully treated with additional SAbR.
The STARTNEWERA phase II trial has reported encouraging long-term outcomes for stereotactic ablative radiotherapy (SAbR) in treating unresectable locally advanced non-small cell lung cancer (LA-NSCLC) patients who are unsuitable for concurrent radio-chemotherapy, with results published in the International Journal of Radiation Oncology, Biology, Physics.
Trial Design and Patient Population
The non-randomized phase II trial enrolled 50 patients across three treatment groups: 23 patients received SAbR alone, 20 patients underwent sequential chemotherapy followed by SAbR, and 7 patients received sequential chemotherapy, SAbR, and immunotherapy. Notably, 76% of primary tumors were centrally located, and 100% of primary tumors and/or nodal disease overlapped with central organs at risk.
The study implemented simultaneous integrated boost (SIB) and personalized simultaneous integrated protection (SIP) techniques, with a median follow-up of 72 months. These advanced radiotherapy techniques may explain the remarkably low toxicity profile observed in the trial.
Safety and Efficacy Outcomes
The trial demonstrated an exceptional safety profile with no grade 3 toxicity events reported throughout the study period. The five-year overall survival rate reached 46%, with a median overall survival of 53 months and three-year overall survival of 70%.
For disease control, the median thoracic nodal recurrence-free survival was not reached, with a five-year rate of 65%. Similarly, the median distant progression-free survival was not reached, achieving a five-year rate of 60%. The median progression-free survival was 13 months, with a five-year progression-free survival rate of 26%.
Local Recurrence Patterns and Predictors
Seventeen patients experienced in-field local recurrence, though the median local recurrence-free survival was not reached, with a five-year local recurrence-free survival rate of 64%. The study identified strong predictors of local recurrence, including squamous cell carcinoma histology and SAbR doses below 40 Gy.
Importantly, 92% of oligometastatic recurrences were successfully managed with additional SAbR treatment, demonstrating the potential for salvage therapy in this patient population.
Clinical Significance and Expert Commentary
Dr. Joe Y. Chang, Endowed Texas 4000 Distinguished Professor and Director of Stereotactic Ablative Radiotherapy Program at MD Anderson Cancer Center, noted the comparability of these results to the landmark PACIFIC study, which showed 43% overall survival and 33% progression-free survival at five years. Chang highlighted the surprising absence of grade 3 or higher complications and suggested that the SAbR approach using gross tumor volume without clinical target volume expansion and a 5mm planning target volume margin may be key to the favorable outcomes.
The trial represents one of the first investigations into the combination of SAbR and immunotherapy in this patient population, potentially opening new therapeutic avenues for patients with limited treatment options.
Treatment Approach Innovation
The study's use of SIB and personalized SIP techniques allowed clinicians to safely deliver effective radiation doses even in the challenging "no-fly zone" of central thoracic anatomy, traditionally considered high-risk for stereotactic radiotherapy. This approach enabled dose escalation while maintaining the excellent safety profile, even when delivering doses under 40 Gy in certain cases.